Improvement in the manufacture of dry white lead



G. T. LEWIS 8513.0. BARTLETT. MANUFACTURE OF DRY WHITE LEAD.

No. 97,936. Patented Dec. 14,1869;

: W g h i \Q. Q i g 5 P: Q? Q J I i g s Fig.5.

, Lead and White-Lead GEORGE r.

LEWIS, or PHILADELPHIA, AND EAYRE o.

BIRMINGHAM, PENNSYLVANIA;

' Letters Patent No:-97,936, dated December114, 1869.

IMPROVEMENT m was menor icronnor nRY-wmi s: 1.241).

The Schedule referred to in these Letters Patent and snaking part of the same.

, metallic lead, by the use of acetic-acid in earthen vessels, immersed in decomposing or ten. V r

This treatment requires from five to twelve weeks,

matter-,surah as dung the lead being aiterwd-rds ground, washed-land-dried I before it is fit to be used as the basis of a pigment. The nature of our invention consists in 'subliming metallic lead andtheuoxidizing the vapors and c01 lecting, them in separate chambers or .bags.

\Ve take metallic lead and finely divide it or granulate it, by slowly pouring it, when melted, from a height of from four to six feet, into water, in a state of agitation. 7

The finely-granulated lead, in smallquantities, is thenmixed with carbon, preferably fine-washed pea or dust anthracite coal, in the proportion of half and half, and the mixture is then heated in a compound reducing and oxidizing furnace. Dense white fumes or vapors pass off. These are conveyed into a separate chamber or receptacle, where the vapors are strained, by passing through bags or screens of muslin, or other fabric, or are allowed to deposit, by being passed slowly throughan extended chamber, in the way in which lamp-black, oxide of zinc, 8m, have been heretofore collected. 1

To prevent the fiuxing of the mass together, and otherwise to facilitate the subsequent operations,

- caustic lime, or the carbonate of lime (in the form of pulverized limestone, or otherwise,) or metallic iron, or its oxides, whether native or artificial, preferably, however, the form known as brown hematite, may be added to the mixture of carbon and granulated lead, in, the proportion of about. two hundred poundsof lime to every four hundred pounds of thelead. This addition is not essential; although under some 'circun1' stances it-is desirable and beneficial. I

' Lead in" this condition will form, when mixed with oil, a superior whitepigmeut. It differs from and is superior in quality, as a pigment, to the white oxide of zinc, oranything heretofore produced from mixed metallic ores, or'to the oxide of lead produced in the ordinary wagihr such purposes as litharge, red lead, or orange mineral are generally applied.

.The product obtained by our said process maybe used not onlyas the basiso'f pigment, "but as a drier,

and in all manufactures where oxide oflead is desired,

The form of the furnace employed is not material,

provided it be so arranged as to evolve metallic vapor,

andthen oxidize the vapor:v

The furnace which of the Unitedstates were granted to Samuel Weth ,erill', November 13, 1855. I,

Thisfurnaoe is ings, in which- 1 v Figure 1 is a plan of the furnace ;v

Figure 2, a front elevation,- Fi nrefi, aback elevation; and

Figure 4, Referring to the drawingsone-quarter of an inch in diameter, and aboutone men apart, and preferably made slightly conical, with the larger diameter downward. The size of the holes would besuch as to prevent .the crushed ore and coal from.

falling through.

These perforated bars are suitablysustained 'at the.

ends out-the front and back wall to (I. The ash pit, below the perforated bottom,

a pipeifrom suitable blowing apparatus.

i, by which it can be closed when workingthe process, or open to remove the residuum, and at the back there are twosliding jams, j j, to give access to the main chamber for stirring the charge, andt'or inspection,

,At the back, near the'arch, there is a holepk, gov erned by a sliding damper, leading to a chimney for carrying off smoke and impure gases in the beginning of theoperation on a new charge-f t In the centre of 'the roof there isian aperture, 1, gov-' crned by a damper or sliding door, in,

vapors of lead. I i r r Theexterior walls at 0 p q may be built above the top, t0 form two feeding-troughs, rr', one on each side of the arch or root, and provided each with an apertureor passage, 8, leading to the inside or main cham-'- her, and each aperture or passage is provided-with a cover, to be put on after the furnace has been charged,

. Having thus describcdour invention, V

Meclaim, and desire to secure bv Letters Patent- BARTLETT, or

wehave found. to work well for the purposes above inentioned,is=commonly known as th'e-Wetherill zinc-furnace, fol-which" Letters Patent 1:epresentedj in,- the annexed draw? a vertical section on ,the line-A a of'fig 1,

, ms the main chamber, the bottom bot which iscom posed of iron bars, perforated with small holes of about is of equal area therewith, and is provided with a door, e, in front, 1 and with a hole, fiat the back, for the reception of leading to a suitable apparatus forthe'collcct-iou of the oxidized 1. The manufacture of the basis of a pigment, by

mixing finely-divided lead with carbon, and subjecting the mixture tothe action of heat in a compound redncing and oxidizing-furnace, and collecting the fumes, as above described.

2. The employment of lime in the form of caustic lime, or the carbonate of lime, or metallic iron, or its oxides, whether native or artificial, in combination with carbon and finely-divided metallic lead, in a, compound reducing and oxidizing-furnace, substantially as described.

3. Subliming the metallic lead, oxidizing the vapors,

and collecting them as formed in a separate chamber, for the purpose of forming a basis of pigment and, for other purposes, substantially as set forth.

4. As a new manufacture, a. white'oxide of lead, produced by snbliming metallic lead and oxidizing the vapors, and collecting them in a separate chamber.

GEORGE '1. LEWIS. EAYRE U. BARTLETT. Witnesses:

W. A. A. MQKINLEY, W. W. DOUGHERTY. 

